A conventional seat which has been proposed allows a trim cover (a surface cover) to be detachably attached to a cushioning material which is formed of a foaming material molded into a seat shape and such seat has been being used for vehicles, etc. Another seat which has been proposed has a cushioning material provided with a drag-in part, in which a trim cover is dragged and fastened by a hook and loop fastener (see, for example, Patent Document 1).